gdrive - Teaching Rounding

Here are some online games to practice rounding:

Mathnook Math Balloons Rounding (rounds to 10, a Tetris like game with balloon popping)
Mathszone scaffolded rounding to 10 using a number line, and rounding to 100
WMNet Postbox HTU rounding to 100 and other games (I am not sure that the <, > one actually works)
Glowia's Estimation Contraption - round numbers to perform quick estimates of addition
Rounding dartboards - not really a game, shows numbers rounded to various levels
IceIceMaybe from MangaHigh - Very cute noisy game where you save jumping penguins by rounding simple calculations to make icebergs